Teardown: Xiaomi 5,000mAh 27W Magnetic Power Bank Pairs SC2017A SoC With WB8128 Qi Transmitter
2026-10-26 · Compiled by Best IT Parts from public industry reporting
Xiaomi's certified 5,000 mAh magnetic power bank, model WPB0525S, carries the GB 47372-2026 marking on a one-piece aluminium body. Bench measurements put the enclosure at 101.03 mm long, 71.54 mm wide and 6.75 mm thick, with the unit weighing 103.4 g against a 105 g nameplate figure. Rated energy is 18.38 Wh, and the port list confirms 27 W wired output plus 20 W maximum on the wireless coil, with both paths usable together at 15 W.
The cell is an ATL 436678N rated 4,850 mAh at 3.79 V, mounted under the main board with a graphite sheet spread across the wireless module for heat diffusion. Instrumented PDO reads show 5 V/3 A and 9 V/3 A fixed profiles plus a 5-11 V/2.45 A PPS range, and a wired charge into a phone measured 26.61 W at 8.94 V and 2.98 A.
Power conversion runs through a Southchip SC2017A in a QFN44 package, which combines a buck controller with a 32-bit Cortex-M0 core, 128 KB of flash, 8 KB of SRAM and an 11-bit ADC. The part exposes two independent CC pairs and DP/DM lines and covers USB PD, BC1.2, UFCS and several vendor protocols, which keeps the external component count and BOM cost low for multi-port designs.
The wireless side is built around a CPS WB8128 30 W Qi transmitter supporting Qi2.2 and MPP, with a 3.3-24 V input window, a QFN31 footprint and 16-channel 12-bit sensing with foreign-object detection. Authentication is handled by a CPS1010 chip carrying a SHA256 engine and ECC signing in DFN8, a HYNITRON HK51BS SOT23-6 sensor detects magnet attachment to wake the coil, and a WCH CH32X035-class MCU services the housekeeping logic.
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Technical details are reproduced as reported. Verify specifications against the original source before design or procurement decisions.